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Imaging quantum stereodynamics through Fraunhofer scattering of NO radicals with rare-gas atoms. Nat Chem 2016; 9:226-233. [DOI: 10.1038/nchem.2640] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 09/08/2016] [Indexed: 11/08/2022]
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Brouard M, Chadwick H, Gordon SDS, Hornung B, Nichols B, Aoiz FJ, Stolte S. Rotational Orientation Effects in NO(X) + Ar Inelastic Collisions. J Phys Chem A 2015; 119:12404-16. [PMID: 26413997 DOI: 10.1021/acs.jpca.5b07846] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rotational angular momentum orientation effects in the rotationally inelastic collisions of NO(X) with Ar have been investigated both experimentally and theoretically at a collision energy of 530 cm(-1). The collision-induced orientation has been determined experimentally using a hexapole electric field to select the ϵ = -1 Λ-doublet level of the NO(X) j = 1/2 initial state. Fully quantum state resolved polarization-dependent differential cross sections were recorded experimentally using a crossed molecular beam apparatus coupled with a (1 + 1') resonance-enhanced multiphoton ionization detection scheme and subsequent velocity-map imaging. To determine the NO sense of rotation, the probe radiation was circularly polarized. Experimental orientation polarization-dependent differential cross sections are compared with those obtained from quantum mechanical scattering calculations and are found to be in good agreement. The origin of the collision-induced orientation has been investigated by means of close-coupled quantum mechanical, quantum mechanical hard shell, quasi-classical trajectory (QCT), and classical hard shell calculations at the same collision energy. Although there is evidence for the operation of limiting classical mechanisms, the rotational orientation cannot be accounted for by QCT calculations and is found to be strongly influenced by quantum mechanical effects.
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Affiliation(s)
- M Brouard
- The Physical and Theoretical Chemistry Laboratory, The Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - H Chadwick
- The Physical and Theoretical Chemistry Laboratory, The Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - S D S Gordon
- The Physical and Theoretical Chemistry Laboratory, The Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - B Hornung
- The Physical and Theoretical Chemistry Laboratory, The Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - B Nichols
- The Physical and Theoretical Chemistry Laboratory, The Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - F J Aoiz
- Departamento de Química Física, Facultad de Química, Universidad Complutense , 28040 Madrid, Spain
| | - S Stolte
- Institute of Atomic and Molecular Physics, Jilin University , Changchun 130012, China.,Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.,Laboratoire Francis Perrin, Bâtiment 522, DRECEM/SPAM/CEA Saclay, 91191 Gif sur Yvette, France
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Warehime M, Johnson ER, Kłos J. New XDM-corrected potential energy surfaces for Ar–NO(X2Π): A comparison with CCSD(T) calculations and experiments. J Chem Phys 2015; 142:024302. [DOI: 10.1063/1.4905252] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michael Warehime
- Chemical Physics Program, University of Maryland, College Park, Maryland 20742, USA
| | - Erin R. Johnson
- Chemistry and Chemical Biology, University of California, Merced, Merced, California 95343, USA
| | - Jacek Kłos
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
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Brouard M, Hornung B, Aoiz FJ. Origin of collision-induced molecular orientation. PHYSICAL REVIEW LETTERS 2013; 111:183202. [PMID: 24237515 DOI: 10.1103/physrevlett.111.183202] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Indexed: 06/02/2023]
Abstract
Collision-induced rotational angular momentum orientation is a fundamental property of molecular scattering, which is sensitive to the balance between attractive and repulsive forces at play during collision. Here, we quantify a new mechanism leading to orientation, which is purely quantum mechanical in origin. Although the new mechanism is quite general, and will operate more widely in atomic and molecular scattering, it is observed here for impulsive hard shell collisions, for which the orientation vanishes classically. The quantum mechanism can thus be studied in isolation from other processes. The orientation is proposed to originate from the nonlocal nature of the quantum mechanical collision encounter.
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Affiliation(s)
- M Brouard
- The Department of Chemistry, The Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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Brouard M, Chadwick H, Eyles CJ, Hornung B, Nichols B, Aoiz FJ, Jambrina PG, Stolte S. Rotational alignment effects in NO(X) + Ar inelastic collisions: an experimental study. J Chem Phys 2013; 138:104310. [PMID: 23514492 DOI: 10.1063/1.4792159] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Rotational angular momentum alignment effects in the rotationally inelastic collisions of NO(X) with Ar have been investigated at a collision energy of 66 meV by means of hexapole electric field initial state selection coupled with velocity-map ion imaging final state detection. The fully quantum state resolved second rank renormalized polarization dependent differential cross sections determined experimentally are reported for a selection of spin-orbit conserving and changing transitions for the first time. The results are compared with the findings of previous theoretical investigations, and in particular with the results of exact quantum mechanical scattering calculations. The agreement between experiment and theory is generally found to be good throughout the entire scattering angle range. The results reveal that the hard shell nature of the interaction potential is predominantly responsible for the rotational alignment of the NO(X) upon collision with Ar.
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Affiliation(s)
- M Brouard
- The Department of Chemistry, University of Oxford, The Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom.
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Brouard M, Chadwick H, Eyles CJ, Hornung B, Nichols B, Aoiz FJ, Jambrina PG, Stolte S, de Miranda MP. Rotational alignment effects in NO(X) + Ar inelastic collisions: A theoretical study. J Chem Phys 2013; 138:104309. [DOI: 10.1063/1.4792158] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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